methods - ComboBox strategies to function -

i have 4 combo box same follows:

select case combobox1.selecteditem case 0  str=str & "' and" case 1 str= str & "'" end case  select case combobox2.selected item  case 0  str=str & "' and" case 1 str= str & "'" end case 

similarly other 2 comboboxes have same body

i want replace code block method call , implement select clause body in method body , call when required.

please give me solution

create method takes input combobox selected index i.e integer in method write follows:

method1(int x) { select case x  case 0  str=str & "' and" case 1 str= str & "'" end case } 

call method1 required.